Electrically conductive organopolysiloxane elastomers which are obtained by cross-linking diorganopolysiloxane compositions containing electrically conductive carbon black are described in British Pat. No. 1,027,051 to Imperial Chemical Industries Limited. Also, British Pat. No. 1,473,371 to Wacker-Chemie GmbH, describes cross-linking of diorganopolysiloxanes containing conductive carbon by high energy radiation.
Compared to the above electrically conductive elastomers, the organopolysiloxane elastomers of this invention have certain advantages over the compositions of the prior art. For example, the electrical resistance of the compositions of this invention increases substantially faster with increasing temperatures, i.e., they exhibit a so-called PTC behavior. Moreover, the steep increase in electrical resistance which takes place at lower temperatures can be predetermined and therefore it is possible to attain a higher specific power density.
It is therefore an object of this invention to provide an electrically conductive composition. Another object of this invention is to provide an electrically conductive organopolysiloxane elastomer whose resistance increases substantially with increasing temperatures. Still another object of this invention is to provide electrically conductive elastomers having higher specific power densities. A further object of this invention is to provide a method for preparing electrically conductive organopolysiloxane elastomers having greater increased resistance with increasing temperatures.